This invention is directed to a loudspeaker and in particular to a multifilar moving-coil loadspeaker.
In a moving coil loudspeaker, the mechanical force on a circular moving coil is developed by the interaction of the current in the coil or coils and the transverse magnetic field disposed radially across a gap in a dc or permanent magnet circuit. The output force which is along the axis of the circular coil or coils is applied to a sound radiator or diaphragm.
Single and multiple moving coil speakers with corresponding circuits have been developed over the years to resolve various problems. Some of these are described in U.S. Pat. No. 1,969,657 which issued on Aug. 7, 1934 to McCaa, U.S. Pat. No. 3,196,211 which issued on July 20, 1965 to Kessenick and German Pat. No. 1,047,843 which issued on Mar. 31, 1960.